rs3077 — HLA-DPA1 HLA-DPA1 3′ UTR variant

HLA-DPA1 rs3077 — Your Immune System's Gatekeeper Against Hepatitis B

The HLA-DPA1 gene¹¹ HLA-DPA1 gene
Human Leukocyte Antigen class II, DP Alpha 1 — encodes the alpha chain of the HLA-DP heterodimer, a surface receptor on antigen-presenting cells that displays peptide fragments to CD4+ T helper cells, initiating adaptive immune responses against pathogens sits at the centre of how your immune system recognises and clears hepatitis B virus (HBV). The rs3077 variant sits in the 3′ untranslated region of this gene — not altering the protein itself, but controlling how much of it gets made. The G allele at this position (equivalent to the C allele on the coding strand in many papers, because HLA-DPA1 is transcribed from the minus strand) silences HLA-DPA1 production in the liver, leaving the immune system less equipped to present HBV antigens and mount a clearing T-cell response.

The Mechanism

HLA-DP molecules are class II major histocompatibility complex²² major histocompatibility complex
MHC — the genomic region on chromosome 6p21 encoding cell-surface proteins that present peptide antigens to immune cells; essential for self/non-self discrimination and adaptive immunity proteins expressed on antigen-presenting cells — dendritic cells, B cells, macrophages, and Kupffer cells in the liver. They display short viral peptides to CD4+ T helper cells, which in turn coordinate antibody production by B cells and activation of CD8+ cytotoxic T cells that kill virus-infected hepatocytes. The rs3077 variant is the single strongest expression quantitative trait locus³³ expression quantitative trait locus
eQTL — a genetic variant that controls the quantity of mRNA produced from a nearby gene; the rs3077 signal for HLA-DPA1 mRNA reached p=10⁻⁴⁸ in a genome-wide scan of liver tissue for HLA-DPA1 mRNA in human liver. Carrying the G allele means liver cells produce less HLA-DPA1 protein — meaning fewer HBV peptides are displayed, CD4+ T-cell help is blunted, and the virus is more likely to establish chronic infection rather than being cleared.

The Evidence

The association between rs3077 and hepatitis B chronicity is one of the most consistently replicated genetic findings in HBV research. A landmark study by An et al. 2011 in 1,742 Han Chinese⁴⁴ An et al. 2011 in 1,742 Han Chinese
A common HLA-DPA1 variant is a major determinant of hepatitis B virus clearance established that the A allele (protective) was associated with a more than doubled likelihood of HBV clearance (OR 2.41, p<0.001) and a 38% reduced risk of chronic infection (OR 0.62, p=0.001). A subsequent meta-analysis of eight studies by Zhang et al. 2013⁵⁵ meta-analysis of eight studies by Zhang et al. 2013
Association of the rs3077 and rs9277535 polymorphisms with HBV infection and spontaneous clearance; pooled analysis of Asian cohorts confirmed an additive dose-response: each copy of the protective A allele further reduces the odds of chronic HBV, with AA homozygotes showing an OR of 0.35 (65% risk reduction) relative to GG homozygotes.

The same signal shapes hepatitis B vaccine response⁶⁶ hepatitis B vaccine response
Standard HBV vaccination induces protective anti-HBs antibody titres ≥10 mIU/mL in >90% of recipients; the G allele at rs3077 is associated with impaired antibody production, making carriers more likely to be non-responders. A Japanese study of 278 healthcare workers found rs3077 was strongly associated with vaccine antibody response (OR 0.32, p=0.010) — GG carriers were disproportionately likely to fail to mount protective anti-HBs titres after standard vaccination. The finding replicated in Caucasian cohorts: Vermehren et al. identified a striking OR of 5.1 (CI 1.9–13.7) for HBV infection risk in European G-allele carriers, confirming the association extends beyond Asian populations.

The G allele frequency varies dramatically by ancestry: only ~17% in Europeans, ~30% in South Asians and Latinos, ~49% in Africans, and ~65% in East Asians — mirroring the global pattern of HBV endemicity and likely reflecting differential historical selection pressure from the virus.

Practical Actions

The clinical relevance of this variant depends on HBV exposure and vaccination status. For unvaccinated GG carriers, routine serology and consideration of enhanced vaccination protocols are the primary actions. For AG carriers, standard vaccination monitoring is appropriate. For those already vaccinated, checking post-vaccination anti-HBs titres is informative given the association with non-response. For those already chronically infected, the A allele at rs3077 predicts better HBsAg seroclearance during antiviral therapy — an important consideration for treatment planning with nucleot(s)ide analogues.

Interactions

The rs3077 signal is part of a broader HLA-DP haplotype. Its partner variant [rs9277535 | HLA-DPB1 3′ UTR — the beta-chain counterpart; commonly studied together with rs3077 as a two-SNP HLA-DP haplotype that additively predicts HBV outcomes], located in HLA-DPB1 (the beta chain gene adjacent to HLA-DPA1), independently tags HBV clearance and vaccine response. The CA haplotype (rs3077 A + rs9277535 A on the coding strand — i.e., plus-strand A at rs3077 + plus-strand A at rs9277535) is more strongly protective than either SNP alone (OR 0.57, CI 0.36–0.92 in the Indonesian replication study). This compound haplotype effect makes a strong case for profiling both variants together when assessing HBV susceptibility.